摘要(英) |
It is known from the old literature that there are two different arrangements of graphene, which result in very different properties. The first one is that armchair graphene nanoribbons have semiconducting properties, and the other is that zigzag graphene nanoribbons have metallic properties, but in terms of thermoelectric materials, armchair graphene nanoribbons have higher thermoelectric figure of merit, so this thes is will focus on this one. Then use electron flow and electron heat flow to deduce conductance, Seebeck, power factor and thermoelectric figure of merit. From the results in the simulation, it can be found that increasing the line width of nanoribbons will cause the bandgap to shrink, which can greatly confirm the effect of Quantum confinement effect. We also observed that the power factor and ZT maxima of armchair graphene nanoribbons mainly occur at the two ends of the bandgap. To have great thermoelectric conversion efficiency, the phonon thermal conductance k_ph should be smaller, while the Seebeck coefficient S and conductance Ge. If it is larger, because these parameters will affect each other,it
becomes difficult to increase the ZT , which is where the current research needs to break through. |
參考文獻 |
[1.]A. J. Minnich, M. S. Dresselhaus, Z. F. Ren and G. Chen, Energy Environ Sci, 2, 466 (2009).
[2] A. F. Ioffe, “Semiconductor Thermoelements and Thermoelectric Cooling”
Infosearch Limited London (1957).
[3] A. Majumdar, “Thermoelectricity in Semiconductor Nanostructures” Science 303,777 (2004).
[4] M. Fujita, K. Wakabayashi, K. Nakada, and K. Kusakabe,J. Phys. Soc. Jpn. 65 1920 (1996).
[5] K. Nakada, M. Fujita, G. Dresselhaus and M. S. Dresselhaus Phys. Rev. B 54, 17954 (1996).
[6] K. Wakabayashi, M. Fujita, H. Ajiki, and M. Sigrist, Phys.Rev. B 59, 8271 (1999).
[7] H. Zheng, Z. F. Wang, T. Luo, Q. W. Shi and Jie Chen,Phys. Rev. B 75, 165414 (2007).
[8] W. Jaskolski, A. Ayuela, M. Pelc, H. Santos, and L. Chico,Phys. Rev. B 83, 235424 (2011).
[9] Y. W. Son, M. L. Cohen, and Steven G. Louie, Phys. Rev.Lett. 97, 216803 (2006).
[10] Y. W. Son, M. L. Cohen and Steven G. Louie, Nature 444,347 (2006).
[11] H. Haug and A. P. Jauho, Quantum Kinetics in Transport and Optics of Semiconductors (Springer, Heidelberg,1996).
[12] Hartmut Haug, Antti-Pekka Jauho,"Quantum Kinetics in Transport and Optics of Semiconductors"
[13] D. M. T. Kuo, AIP Advances 10, 045222 (2020). |